braincrafted/bootstrap-bundle — pull request #20 by danielkolvik (2013-02-27 19:26:11+00:00)
Title: Add icon to prepend input field

This request adds the possibility to add an icon to input fields as shown in http://twitter.github.com/bootstrap/base-css.html#icons under the Form fields section.
This is done by extending the prepend input behaviour.

To add an icon to your text/number input field, simply add an array to prepend input with the icon name.

Example:
```php
$builder
->add('start_date', null, [
'widget' => 'single_text',
'format' => 'yyyy-MM-dd',
'attr' => [
'class' => 'datepicker span2',
'prepend_input' => [
'icon' => 'icon-calendar'
]
]
]
);
```